In general terms, this invention relates to vehicle weight classification systems for classifying the weight of an occupant on a vehicle seat. More particularly, this invention relates to a signal processing system and method for handling sensor signals used in a vehicle weight classification system.
Contemporary vehicles typically include safety restraints to protect passengers and drivers during impact. Such restraints include seatbelts and airbags, for example. It has recently become apparent that customized control of airbags is desirable. The owner of this application has developed a weight classification system that is useful for determining the size or weight of a seat occupant and controlling an airbag deployment responsive to that determination.
One of the challenges in designing a weight classification system is keeping the system simple and robust. In order to do so, choices must be made regarding the types of components utilized as sensors and signal processing, for example. There are competing concerns between system performance (i.e., accuracy), cost and durability of the system components. These various factors present complicating and sometimes competing interests for designing such a system.
In addition to the system constraints, there are a variety of factors that must be accounted for when operating a weight classification system. Certain factors affect the performance of the system. Such factors include for example, temperature, sensor offset, signal strengths and the capabilities of the various components used in the system. There is a need for a way of addressing the various issues that must be compensated for when operating a weight classification system.
This invention provides a unique approach to addressing the various influences on the operation of a weight classification system.
In general terms, this invention is a system for compensating for various factors that influence the operation of a vehicle weight classification system. This invention includes the identification of various factors that must be compensated for in handling signals in a weight classification system. Some of these factors are compensated for using analog signal processing techniques. Other factors are compensated for using digital signal processing techniques. The combination of analog and digital approaches provides a solution that adequately addresses the various and different concerns raised when operating a weight classification system while keeping the system cost and complexity within acceptable limits.
The various features and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the currently preferred embodiments. The drawings that accompany the detailed description can be briefly described as follows.